i was looking at buying one of this for my 10 gallon test project but measured out my tanks rim dimensions to be 9 1/2" x 19 7/16" and the website says

NOTE: This kit is designed for aquariums with a rim opening of 9 3/4" x 19 1/2". Custom sizing available on request at an additional cost.

Johnny are you still around? Any way you could check the measurements of the kit? I've measured a few different brands of 10 gallons and haven't found one that has the rim dimensions they specify for the kit